EXPLANATION
This test method covers the determination of pour point of petroleum products by an automatic instrument that applies a controlled burst of nitrogen gas onto the specimen surface while the specimen is being cooled and detects movement of the surface of the test specimen with an optical device. This test method includes the range of temperatures from -57 to +51° C. Test results from this test method can also be determined at 1 and 3 ° C testing intervals; however, precision data of these testing intervals are not available. This test method is not intended for use with crude oil. The applicability of this test method has not been verified for residual fuel samples.
TEST SUMMARY
After inserting the test specimen into the automatic pour point apparatus, and initiation of the test program, the test specimen is heated and then cooled by a Peltier device at a rate of 1.5 +/- 0.1° C/min. At temperature intervals of 1, 2 or 3 ° C, depending on the selection made by the user, a moving force in the form of a pressurized pulse of nitrogen gas is imparted onto the surface of the specimen. Multiple optical detectors are used in conjunction with a light source to monitor movement of the surface of the specimen. The lowest temperature at which movement of the specimen surface is observed upon application of a pulse of nitrogen gas is recorded as the pour point, Test Method ASTM D5949.
TEST PRECISION
